Prepayment mechanism



vJune 23, A1942. G., E, WESTON 2,287,363

PREPHMENT'Mlazcmfmsm Filed Feb. 1,2,r 1958y y a sheets-sheet 1 M, um

June 23, 1942. G. E. wEsToN PREPAYMENT MEGHA'NISM Filed Feb'. 12, 1938 l a sheets-sheet 2 Hmm@ n George dumrd Zdeson/ @mmf-M y ,MQW-

June 2351942., G. EQ WESTQN 2,287,363'

PREPAYMENT MECHANISM,

Filed Feb; 12, 1938 a sheets-sheet s m N m l0 '.0 N

y L y mentor Georg@ Edward Zzforb June 23 942- G. E. wEsToN PREBAYMENT MECHANISM Filed Feb. 12, 193s' 8 Sheets-Sheet 4 Jzwenoz." l .Georga Edward weson/ G. E. WESTON PREPAYMENT MECHANISM June 23, 1942.

Filed Feb. 12, 1938 8 Sheets-Sheet 5 June 23, 1942, G. s. wEs'roN 2,287,363 PREPAYMENT MEcHANI-SM 4 Filed Feb. 12, 1938 8 Sheets-Sheet 6 O in June`23, 1942. G, E, WESTON 2,287,363

PREPAYMENT MEGHANISM med Feb. 12, 1938 8 sheets-sheet 'r WA TT-HUI? METER 42 VJunezs, 1942. G, WESTON 2,282,363

PREPAYMENT MECHANISM Filed Feb. l2, 1958 8 SlleetS-Sheeil 8 fpe ZT M6140@ Patented June 23, 1942 PREPAYMENT MECHANISM George Edward Weston, Enfield, England, assignor to Sangarno Electric Company, Springfield, lil.

Application February 12, 1938, Serial No. 190,180 fn'Great Britain February 16, 1937 7 Claims.

The present invention relates to prepayment mechanisms which, while particularly applicable to the controlling of electric supply meters, are also capable of application in a much wider sphere as will readily be appreciated.

The principal object of the invention is to relieve the user of the necessity of effecting some or all ofthe operations incidental to the insertion of a coin; which operations consist, for instance, in gauging the coin, setting gear mechanism in accordance with the Value of the coins, operating the gear mechanism in accordance therewith, operating a device to effect the supply of the commodity (for instance in the case of an electric supply meter, closing the switch) rejecting faulty coins, collecting the coin after gauging has been completed, and testing coins for various properties.

Another object of the invention is to prevent any access to any part of the mechanism through the coin insertion or like aperture during the whole of the period of time when the various operations incidental to the insertion of such coin are being effected.

Another object of the invention is to provide an improved arrangement for receiving the inserted coin whereby provision may be made for the insertion of extra thick coins such as the new British threepenny piece, while at the same time avoiding the possibility of jamming of the apparatus by the simultaneous insertion of two thinner coins.

A further object of the invention is to provide an improved coin testing mechanism for checking both the diameter and the thickness of the inserted coin.

Another object of the invention is to provide an improved switch setting and tripping mechanism by which the frictional load imposed upon the meter mechanism controlling such switch is reduced or avoided.

Yet a further object of the invention in the case of its application to electricity meters, is to provide a warning for the user that his credit is approaching exhaustion while another object is to improve the means for handling unsuitable coins.

According to one feature the invention as applied to a multi-coin prepayment meter for electricity or gas, consists of the employment of an auxiliary source of power such as supply of electricity or a stressed spring for effecting certain or ail ofv those operations which are normally performed by the user.

According to a supplementary feature of the invention in particular connection with devices operable by any one of a number ofv differently valued coins, the operator effects an initial step such as inserting the coin and releasing or otherwise permitting the movement of a device whereby the coin advances to a position which it could only reach by such movement or gauging of the coin and thereby closing one of' a numberof different electrical circuits according to the diameter of the inserted coin, a circuit closure following upon such initial stepy resulting in the remaining operations being brought about automatically.

According toyet another feature ofthe invention the whole ofthe operations are effected independently of the userr once the coin slot has been opened, the coin inserted and the coin slot reclosed.

According to yet a further feature of the invention a coin receiving chamber or cage is provided which is movable to receive an inserted coin and also to prevent the insertion of coins of more than a total predetermined thickness.

According to a further feature of the invention the auxiliary driving power source is put into operation by the insertion of a coin and continues to operate the meter mechanism through a complete cycle of operations irrespective of whether the inserted coin is satisfactory or not, but onlyv effects a registration of the Value of such coin if it passes all of the tests applied to it.

According to a further feature of the invention as applied to prepayment meters for electricity a device is provided by which an interrnittentV interruption of the supply is effected immediately prior to the point of cutting-off of the supply by the meter mechanism due to exhaustion of the users credit therein.

In order that the above and further objects and features ofthe invention may` be more readily understood a constructional embodiment will now be described with reference to the accompanying drawings, wherein:

Fig. l isa frontf elevation of a prepayment mechanism according to the present invention in association with anv electric-watt-hour meter mechanism; v

Fig. 2 is ai plan View ofthe mechanism. shown in Fig. 1;

Fig. 3 is aseotional elevational View drawn to an enlarged scale and taken along the. line III-III ofFig. 2S;

Fig. 3A is a detail View showing a portion of the arm H8 and the cam' H59` in elevation;

Fig. 3B? is a top plan view pf the slide plate I42a, showing its relation to the pin |4217, just prior to engagement therewith;

Fig. 4 is a sectional elevational view also drawn to an enlarged scale and taken along the line IV-IV of Fig. 2;

Figs. 5 and 6 are fragmentary plan views showing the construction and manner of operation of the coin receiving mechanism;

Fig. 7 is a fragmentary plan view showing the calipering and thickness testing mechanism;

Fig. 8 is a circuit diagram of the driving motor and its controlling switch contacts;

Figs. 9 and 10 are detail views taken at right angles to one another of the switch closing and latching mechanism and part of the automatic warning device;

Figs. 11 and 12 are detail views of the device for giving warning to the user of impending exhaustion of credit;

Fig. 13 is a schematic view lshowing the arrangements of the various gear trains of the meter mechanisms;

Fig. 14 is a diagrammatic view in perspective of a modication;

Fig. 15 is a plan view of certain details of construction shown in elevation in Figs. 3 and 4;

Fig. 16 is vertical sectional view of certain details of the warning mechanism; and

Figures 17 and 18 are different views of a gear shifting lever.

Figures 1 and 2 show the prepayment mechanism indicated generally by the reference numeral I0 located within a casing A and provided with a device II for collecting a fixed charge and attached to a watt-hour meter or integrating mechanism I2. The latter may be of any desired and known construction giving a rotary movement proportional to the consumption being measured and in the example shown comprises the usual disc-motor element I3 carried upon a motor shaft I4 and moving between pole tips I5. The motor shaft I4 drives the gear wheel I6 through a suitable reduction gear train and also operates an integrating gear train actuating a plurality of recording dials I1.

The prepayment mechanism I0 (see more particularly Figures 1 to 4) comprises generally a coin receiving mechanism I8 for dealing with the coins fed to the mechanism by the user, coin testing mechanism I9 to which coins are fed by the coil receiving mechanism and by which the inserted coins are tested with regard to certain properties such as diameter, thickness and electrical conductivity so that the subsequent operation of the meter can be controlled in accordance with the results of such tests, switch closing mechanism 20, registering or credit mechanism 2| iniluenced in one (i. e. crediting) direction by operation of the coin testing mechanism I9 upon an acceptable coin and in an opposite (i. e; debit or arrears) direction by movement of the watt-hour meter mechanism I2 and the xed charge collector I I, switch controlling mechanism 22, Figure 9, influenced by the setting of the registering mechanism 2I, automatic credit exhaustion warning device 23, Figure 9, and an auxiliary driving power source in the form of a drivingmotor 24 for effecting the whole of the operation of the mechanism at each coin insertion without any manual effort over and above that of inserting a coin into the mechanism.

The coin receiving mechanism illustrated more particularly in Figures 1, 2, 3, 5, and 6 comprises a coin cage 25 formed of insulating material such as a moulded plastic material, secured to the upper end of a lever 26 pivoted at its lower end at 4I to one of the frame-plates 21 of the mechanism. A masking plate 28 provided with a restricted coin slot 2S is secured to the front of the cage 25 and slides upon the rear surface of a stationary block 39 secured to the front frame-plate 21. The block 30 is provided with a coin insertion aperture 3| therein at a position normally out of register with the slot 29 and also has a manually operable flap 33 secured to a spindle 32 pivotally mounted therein. The spindle 32 has a forked lever 34 secured thereto at its upper end. The fork of this lever receives one end of a spring 35 secured at its other end to the top of the cage 25. This cage is normally urged to occupy the position shown in Figures 2, 3, and 5 by a helical spring 36 anchored at one end to the cage and at its other end to the block 39; this spring, acting through the spring 35 which is much stronger than the spring 36, also serves normally to-maintain the flap 33 closed upon the insertion aperture 3|.

The interior of the cage 25 is of considerably greater width than that of any coin or plurality of coins that it is possible to insert through the coin slot 29 and the insertion aperture 3| and is provided in one side wall thereof with an transverse slot 31 which permits the passage into the interior of the cage of one edge 38 of an abutment plate 39 fixed to one of the frame plates 21. The edge 38 is stepped by means of an inclined surface 40 to provide a proud portion 45 which causes the effective width of the coin cage 25, when its slot 29 is in register with the aperture 3|, to be less towards the back than at the front. The cage 25 moves about the pivot 4| with its open bottom aperture 42 located immediately above the upper surface of a platform 43 formed upon a second or coin testing chamber 44 in all of its positions except its extreme left-hand or normal position (Figures 2, 3, and 5) where the bottom aperture 42 is in register with the lower chamber.

'Ine coin testing chamber 44 is formed with two spaced-apart side walls 46, 41, and a rear end wall 48. The chamber is formed of insulating material, such as a mouldable plastic material, and is provided with a metal insert or plate 49 on the inner surface of the side wall 46 and with a hinged light metal nap 50 secured to the inside of the opposite side wall 41. These metal members are located adjacent the rear wall 48 and form one electrical Contact for engaging an inserted coin. The bottom of the coin testing chamber 44 is normally closed by a member 5I of sector-shaped cross-section also formed of insulating material and provided with a metal top plate 52 constituting a second electrical contact for engaging the inserted coin.

The member 5I is secured near its lower edge Y upon a spindle 53 pivotally mounted in the frame plates 21. This spindle is provided near its rear end with a two-armed catch lever 54 (Figure 4) which serves to control the movement of the member 5I in a manner hereinafter described.

The operation of this portion of the device which requires a manual movement to effect each coin insertion is as follows. The flap 33 is opened manually, thereby rocking the forked lever 34 to the right (Figure 6). This operation moves the cage 25 bodily through the stiff spring 35, and stresses the helical spring 36 until the slot 29 in the masking plate 28 comes into register with the coin insertion aperture 4| in the block 30. A coin or like article can now be inserted and if it is not more than a certain predetermined thickness it will pass into the cage between the lefthand wall thereof (Figure) and the proudlportion 45 of the'abutment'plate 39. Release of the flap 33 will then allow the spring 36 to causethis to close and the cage to move to the left (Figure 5) with the coin therein resting upon the platform 43 until the bottom aperture 42 of the cage registers with the coin testing chamber 44, whereupon the coin or like article will drop into the latter for further handling.

In the event of excessive thickness of theicoin',A or in the event of the insertion of a-pluralityof Y thin coins at one time through the aperture 3| and the slot 29 such coin orcoins will comefinto engagement withv the inclined surface 49 ofthe 'xed-abutment plate-39 andupon furtherforcing pressure being applied will be forced between theproud edge portion 45 andthe opposing wall of the cage. Such action'will result in bodily movement of the cage-to the left, such movement being permitted without closure ofthe nap 33 by the flexing ofthe stil-fspring 35. This movement of the cage will result -in equivalent movement of the masking plate 28 with theY result that-the coin slot 29 will no longer be in exact register with the aperture 3| and the effectivepassagewayis decreased in width toprevent the insertion'of further coins. AV similar action takes place-if attempt is made to insert a secondl thin coin after a rst coin and while it may be'possible to force a coin or coins into the cage, such action automatically causes a restriction in` size of the insertion aperture available-thereaftercoin of excessive thickness but small diameter is to be dealt with, in addition to the usual rangeY of coins, the inclined surface 49" isarranged in such a position that the said thick coin can be accommodated wholly within the cage without having to ride up vthe said inclined face. After insertion of the coin (or coins if one or more further coins have'been forcibly inserted in the manner described above) the release of the flap 33 causes the movement ofthe cage away' from the abutment plate 39 with the result that the coin (or coins) are loosened within the cage and are perfectly iree to drop into the coin testing chamber 4d when the cage bottom aperture 42 registers therewith. 1t will also be appreciated that the masking of the coin passageway by the flap 33 and the masking plate 28`prevents any possibility of access to the interior of the mechanism through such slot.

The coins or other article thus delivered to the chamber 44 drop between' the metal plate 49 and the ap 59'and rest upon the contact plate 52 of thesector shaped coin chamber closing member 5| that is mounted on a shaft 53; If, as is the case with a coin, the inserted article is conductive the electromagnetic auxiliary driving power source or motor 24 is immediately actuated.

The circuit diagram of Figure 8 shows how a conductive coin .r bridges the contacts 49, 50, and

52 to complete a circuitfrom mains lead 56 through an electromagnetic driving motor coil 5l of the motor 24 to the other mains lead 58; Immediately the motor 24 commences to operate, it completes at contacts 59 a further circuit shunting the coin contacts 49, 59,' and 52. These shunting contacts 59 are, as illustrated in Figure 4, controlled by a cam 59 secured to a shaft 6|- which is in driving connection with the motor 24 and makes one revolution for every operative When, as inY the case of the new British threepenny piece, a

cycle of the mechanism. It will be seen th'at'the relieved portion ofthe cam Si) (Figurel) is nor# mally` oppositev a 'projecting' cam follower 69a, von the switchA contacts 59 and these are thus open;

' Upon initial energization of the motor 24 throughY thek coinbridg'ed' contacts the cam -69 is moved suii'icientl'y to cause closure of contacts 59 which are-then' maintained closed, irrespective of the removal' of 'the coinfrom the chamber 44', until the cani has completed.k one'revolution' back toits initialv position where; the coin having meanwhile been removed' from'the chamber 44, the motor circuit is broken. The contact pressure between the hinged flap 59 and the opposing metal insert 4l is regulated to be as light as possible in order to avoid holding of the coins out of contact with the contact plate 52a This regulation is effected by means of a bellcranklever 62 (Figure 3) YpiV'- oted at tte one of theframeiplates 21 Vand-provided' at its upper end With'anose piece 94 of 'insulating material projecting through an aperture inthe side wall '4l of. the chamber 44 to engage the flap 59. The pressure of the nose 64 upon the flap is regulable by a counterweight G5 secured to 'the other armV of the lever $32 while a lug Gois also provided on the' said lever in the path of the sector-shaped member 5l for a purpose hereinafter described.

The auxiliary driving rpower source is in the form of an alternating current motor 24. This motor comprises a laminated eld structure (57Y provided with the coil 5l and an armature tunu nel 69 containing a polarised armature e9 loosely mounted on a rotatable shaft l@ carried in hearing plates ll secured to the eld structure el.

The armature 59 is anchored at one end to each side Yof the armature tunnel by opposed springs l2 which allow the armature to vibrate when alternating current is fed to the winding 5l;

This vibratory motion of the armature is translated into unidirectiona1 rotary motion of the shaft l@ by means of a pair of pawls i3 carried by the armature engaging a ratchet wheel i4 secured to the shait, any backward movement of the shaft being prevented by further pawls l5 secured to the bearing plates 'il and also engaging the said ratchet wheel. It will be understood that any other suitable form of driving motor may be employed depending upon the current supply available.

The coin testing mechanism |9'will new be described. The motor shaft 'I9 carries at one end a pinion 'le (Figure ll) driving through idler gears Ti, a spur wheel 'i'rigidly secured to the shaft 5|. The spur wheel l'meshes with an identical spur wheel 79 carried by but not positively xed to a spindle 9e also rotatably mounted in the frame plates 2l.

The thickness testing section of the coin testing mechanism comprises a cam |29 rigidly secured to the shaft El and having a notch |2| in its periphery which latter is engaged by the nose |22 of a lever |23 pivoted at its upper end |24 to one of the frame plates 2l. This lever carries a plunger rod |25 arranged to pass under the action .of a spring |27, through a hole lt (Figure '7) in the side 47 of the chamber 44 so as to engage the thickness dimension of any coin therein. The lever |23 extends downwardly and is provided with a tail |28 which can, under some circumstances, engage a part |34 of a detent device |29 carried by a shaft |59 which is provided at its rear end (Figure 4) with an arm 3| acting upon a pin |32 secured in a pivoted bar lle. The detent device |29, shown in detail in Figure 15, comprises an arm 250 rigidly secured to the shaft |30 and provided with a projecting lug 25|. The part |34 is loosely mounted on the shaft |30 and rests upon a set screw |33 which projects through the lug 25|, Figure 3. The position .of the part |34 is adjustable with respect to the shaft |30 by adjustment of the set screw |33. The bar is pivoted at one end to the frame and is spring urged upwardly against a stop pin 252 by a spring 253 and at its other end has a projecting lug l normally engaging the catch lever 54 secured to the spindle 53 and controlling the member 5| closing the chamber 44.

In the operation of this part of the coin testing mechanism, upon rotation of the shaft 8| by the power source 24 in the direction indicated by the arrow 8|a, Figure 3, the nose |22 drops into the notch |2I and allows the plunger rod |25 to project into the chamber 44. Such movement causes the tail |28 .of the lever |23 to move towards the detent device |29. This device |29 is so adjusted as to its position that the tail |28 of the lever |23 does not engage therewith when the plunger rod |25 contacts with a coin of at least a certain predetermined thickness within the chamber 44. If, however, the coin is of less than such predetermined thickness or is absent or pierceable the tail |28 moves far enough to engage the part |34 and so to rock the device |29, the shaft |30 and the arm |3| which in turn depresses the bar ||0 against the action of spring 253 to remove lug from engagement with catch lever 54. Such release of catch lever 54 permits the spring |l2 to move the coin chamber closing member 5| to the left (Figure 3) in a direction to pass the coin down the rightmhand side of the member 5| to the returned-coins chute or the like. The member 5| is rocked in the opposite direction (to the right Figure 3) if the coin has proper dimensions in a manner hereinafter described.

The plunger rod |25 is almost immediately retracted by the cam |20 and the coin if of wrong thickness or pierceable is thus removed from the chamber 44 before the calipering operation which follows immediately takes place.

In order to avoid any possibility of light cardv board discs or light metal slugs being retained between the flap and the plate 49 the member 5| is arranged to engage the lug 66 on the bell crank 92 during its rocking movement to discharge a coin and thus to remove any pressure of the nose piece 04 upon the flap 50.

The diameter calipering section of the coin testing mechanism comprises a snail cam 8|, Figures 3 and '7, rigidly secured to the shaft 6| and having a contoured surface engaged by a cam follower 82 integral with a sleeve 83 which is freely rotatable about a vertical spindle 84 rotatably mounted in bearing brackets 85 secured to the front plate 21 of the mechanism. The spindle 84 has a lever having two arms 86, 81 (Figures 3 and '7) rigidly secured thereto, one arm 86 .being linked to a calipering slide 88 mounted for transverse movement across the coin testing chamber 44 and acting to caliper the diameter of a coin located within the testing chamber. The other arm 81 is provided at its end with a roller 81a retained within a. groove formed in a multiple section gear unit 89 and operates to slide the latter along the squared portion of the spindle 80. The ratio of lengths of the arms 85, 81 is made such that the moVe- 75 ment of the gear unit 89 is an amplified version of the movement imparted to the slide 88.

The spindle 84 and the lever 86, 81 are connected to one end of a helica1 spring |04, Figure 3, anchored at its other end to the fixed frame of the mechanism. This spring |04 acts to urge the lever 86, 81 in a direction to move the calipering slide 88 against a coin in the chamber 44 but is prevented from such action when the follower 82 is resting against the proud part of the cam 8| by the opposition of the stronger helical spring |05 connected between the cam follower 82 and the spingle 84.

When the cam follower 82 rests against the cam 8|, as shown in Figures 3 and '1, it acts through the relatively strong spring |05 to hold the spindle 84 and therewith the lever 86, 81 against the biasing force of the relatively weak spring |04 with the calipering slide 88 in the inoperative position, Figure '7. The spring |05 permits continued movement of the cam follower after the calipering slide 88 has been fully withdrawn from the coin chamber 44, thus ensuring that it is completely withdrawn. It will thus be apparent that the cam 8| and its follower 82 serve to move the calipering slide 88 into and out of operative position in the coin chamber 44, the final calipering movement being under the control of the relatively weak spring |04. Also, the multiple unit gear 89 is moved together with the lever 86, 81 back to their initial positions by the cam 8| following completion of the coil calipering cycle. Since the movement of the lever 86, 81 depends upon the size of the coin being calipered and is, of course, variable some such connecting mechanism such as that described employing the springs |04 and |05 and associated parts must be used to perform all of the required operating functions.

In the operation of this section of the coin testing mechanism, the rotation of the shaft 8| and cam 8| releases the cam follower 82 which can then move towards the shaft and relieve the tension on spring |05. The spring |04 now becomes effective to urge the slide 88 against any coin located withinv the chamber 44 and the nal position in which such slide abuts the coin determines the axial position of the gear unit 89 upon the shaft 80.

The multi-section gear unit 89 is provided with a notched disc |06 which is adapted When the spindle is rotated (through gears 18, 19) by the operating motor 24 to co-operate with a gauge plate |01 rigidly secured to a rock bar |08 carried in the frame plates 21. The gauge plate |01 is provided with a plurality of spaced slots located in positions which register with the disc |08 when the gear unit 89 is in any one of its positions corresponding to the calipering of a coin of acceptable diameter within the chamber 44. The alignment of the notched disc |06 with any one of these slots permits continued rotation of the gear unit 89 by the motor 24 through gears 18, 19 and shaft 80 and thus effects an appropriate amount of rotation of a gear wheel 90 in accordance with the value of the coin located within the chamber 44. For such purpose the multi-section ear unit 89 is provided with a plurality of axially spaced sets of teeth adapted in the manner above described to be brought into alignment with the gear wheel 90 secured to a shaft 9| also rotatably mounted in the frame plate 21 and in geared relation to Aside thereof (Figure 3) action of spring 4the credit registeringmechanism 2| in a manner hereinafter more `fully described.

In the event -of calipering ofra coin of incorrect inacceptable diameter'within the chamber 44 the notched disc |35 ywill not align with any slot of the gauge plate |37 and in consequence, during rotation of the spindle 8|? by the driving motor, thesaid dis-c will engage the gauge plate and cause a rotary movement of the rock bar |08 against the action of a spring 55 (Figure 4). This rock bar is secured at its rear end to a trip lever |ii9 (Figure 4), which bears aty its lower end upon an abutment |330, secured to the pivoted bar lli). Upon movement of the rock bar |58 by the disc |36 the pivoted bar li is depressed, the catch lever 54 released and the melon ber 5| rocked about its pivot towards the left (Figure 3) by the spring H2 to allow the coin within the chamber144 to fall on the righthand into a returned-coins chute or container. 'Referring now to Figures 4 and 7 the spur wheel 'I9 which is freely rotatable upon the shaft 35, is provided. with. a pin ||3 normally projecting into engagement' with the laterally projecting end li-ct of a lever ||4 pivoted upon a plate H5 in rigid driving connection with the shaft 30. This lever its is provided with a pin H5 projecting .through an arcuate slot in the plate H5 into a plane where, upon rotation of the wheel 'i9 and the plate H5 in unison therewith, it will come under the nose of the trip lever |39 so that if this latter should be rocked aboutits axis at this same instant by engagement of the notched disc |33 with the gauge plate I3?, then the pin`||5 is depressed towards the center of the wheel i9 against the ||4b and the lever H4 thus `moved out of engagement with the pin H3. In this :manner the spur .gear wheel 'i3 is freed and Ypermitted to continue its rotation by the comn pletion of the operative cycle of the motor 34. The partially rotated shaft 8G is then retracted to its initial position by the pressure of a camfaced arm ||8 (Figure 3) urged by va spring H3 upon a cam i9 carried by the said shaft The arm ||8 and cam H3, Figure 3A, are each provided with cooperating flat surfaces |i3a and ISa respectively and are so arranged that when the shaft 84 is moved to the position where it is released from connection with the gear wheel l5), the said surfaces I8@ and |911 lie at an acute angle to one another. The pressure of the arm H8 thus tends to return the shaft 83 to its original position. The rock bar |63 on being relieved of the pressure of the notched disc |35 alsoreturns to its normal position under the action of the spring 55. v

The coin cage 25 is provided with a pivotally mounted gravity pawl |35 (Figures 3, 5, and 6) carrying a pin |35;` on a nose 31 thereof. A two armed lever |33 pivotally mounted on a frame plate 2l hasits upper end located within the path of thepin |36 during the movement of the cage 25 to the right (Figure 3) for the purpose of inserting a fresh coin therein. This engagement between the pin |35 and the lever` |33 causes the lower end of the latter to engage the member 5| and thus to rock it to the left (Figure 3) andso cause the discharge of any object within the'coin chamber 44 to the returned coins chute or the like. By this means it can be ensured that articles which are non-conductive in character and hence will fail to start the operrating motor, will be discharged during the next following coin-insertion Aoperation and will not clog the device.

A three-armed star-shaped member |39 also pivotally mounted on a frame :plate 2'| Vhas one arm provided with a magnetic armature' |40 arranged to be attracted'by the :pole tips of the field structure 61 when the motor 24 is energized. The rotationof this member |39 by such energisation causes a flap |4| of insulating material carried by another arm thereof to be brought up into a position where it obstructs the top of the chamber 44 and prevents the passage of any further coins thereinto, while at the same time the remaining arm of the member |39 raises the gravity pawl |35 into a position where the pin |34` cannot engage the lever |38 to cause the release of the coin within the chamber 44. In this manner the feeding of further coins to the device While one is being dealt with or the premature release of the actual inserted coin is prevented.

For the purpose of preventing overloading of the credit-storing mechanism by the insertion of an excessive number of coins at any one time a sliding plate |42 (Figure 3) is carried by a suitable bracket extending from the frame and is Drovided with a lug |42a arranged 4to be engaged by a pin |421) carried upon a gear wheel |34 of the registering o-r crediting mechanism 2|. This gear wheel, shown more clearly in Figure 1'0, is adapted to be moved along a helical path by the bodily rotation thereof along a screwed shaft |53 in one (i. e., a debit) direction by the meter and fixed charge mechanisms |2 and`|| respectively and in the opposite (i. e., credit) direction by the gear in known manner. VWhen the gear wheel |64 has been advanced as .far as is allowable in the credit storage direction, the slide plate |42 is moved by engagement of its turned up end |42a, Figure 3B, with the pin |4225 and through `a linking spring |93 causes the rocking of a lever |94, pivoted to the frame at |35, in such a direction that its upper end |55 engages the edge of the 4flap |4| and moves the latter into its position obstructing the top of the chamber 44 thereby preventing the feeding of further coins into the device. It will be recalled that the flap |4| is carried by one arm of the star-shaped member |33 which is normally controlled on energization of the motor 24 by the plate`|4|l of magnetic material being attracted by a portion of the leakage iluX of the motor. Movement of the flap |4| is also controlled by the lever |94 whose upper end |95 is yarranged to engage and move the flap |4| when maximum credit has been registered so that no additional coins are` permitted to fall into the coin chamber 44. Any coins still remaining in the cage 25 will thus be held until the gear wheel |64 has retracted slightly to permit removal cf the flap I4I.

The continued rotation of the driving motor 24 effects a complete revolution of the spur gear gear wheels 18 and 19 and at a position near the completion of one revolution thereof a pin |43 (Figure 4) on spur whel v'I8 engages the end of the catch lever 54. If a satisfactory coin has been dealt with this lever is still in the position shown and in consequence the pin |43 causes its rotation in an anticlockwise direction (Figure 4) to cause rocking of the member 5| to the right (Figure 3) and so cause discharge of the proper coin within the chamber 44 to the left of the member 5| into a coin till. It will be understood that this operation is only eifective to discharge the coin into the coin till in the event of a proper coin since the member will in all other cir-cumstances have already been moved to the left (Figure 3) to discharge the coin into the return chute at some point of the operative cycle prior to the operation above described. If, on the other hand, owing to rejection of a faulty coin this lever has been tripped by lowering of the lug then the pin |43 will engage within the fork 54a of the lever 54 and rotate it in an anticlockwise direction to an extent suflicient to restore its lower end behind the lug I I ready for the next operation.

The switch closing and controlling mechanisms will next be described. The spur gear wheels 18, 19 are each provided with an axially projecting pin |44, |45 respectively and positioned so that they both rotate in unison but in opposite directions.

Referring now to Figures 9 and 10 showing the rod |41 provided at its upper end with a top plate |48 and carried in a bearing bracket |49 secured to one of the frame plates 21. A helical compression spring |50 is located between the upper surface of the bearing bracket |49 and the top plate |48 and encircles the rod |41. A further helical spring |5| surrounds a switch rod |52, preferably of insulating material, and is secured at its upper end to this rod and at its lower end to the plate |46. The switch rod |52 is arranged for vertical sliding movement within the two plate members |46 and |48 and also in an extension of the bearing bracket |49. rIhis rod carries the movable contact of a mercury switch |53 of any suitable form controlling the main current supply from the supply mains to the users circuit. The upper end of the switch rod |52 is provided with a latching abutment |54 which co-operates with the upper end of a latching lever |55 which is pivotally mounted to a frame plate 21 and has a lower end projecting within the path of a radially extending pin |56 secured in the shaft 80.

The plate |46 when fully depressed by the pins |44 and |45 depresses the end of a catch lever 51 pivotally mounted upon a spindle |58 carried in the main frame. This lever |51 has a lower end |59 provided with a chamfered cam surface |60 and an abutment surface |66a which cooperates with a collar 6| secured to an axially movable shaft |62 which is coaxial with the screwed shaft |63 carrying the trip wheel |64 of a known form of credit registering mechanism indicated generally by the reference numeral 2|. If such credit registering mechanism is registering credit the abutment surface |69a of the end |59 rests upon the collar |6| as shown in Figures 9 and 10.

The operation ofthe switch closing mechanism is as follows. During each cycle of operation of the motor 24 the pins |44 and |45 are rotated in unison and if the switch is open, bear upon the plate |46, depress this with the top plate |48 to compress the spring |50 and to extend the spring |5| since the switch rod .|52 will be held latched at its upper end by the engagement of the lever |55 underneath the abutment |54. At the lowest point of movement of the plate |46 and providing the credit registering mechanism 2| has been placed in credit the plate |46 Ywill be latched by the tongue |66 of the lever |51 the latter lever being held in the position shown with the abutment surface |6601I of the end |59 thereof resting on the edge of the collar 66|. The end |59 of the lever |51 assumes this position by reason of the chamfered end |60 acting upon the collar |6| and causing a small and temporary movement of the shaft |62 forwardly against a spring |92. Near the end of the operative cycle of the mechanism when dealing with a satisfactory coin the pin |56 on the shaft will engage the lower end of the latching lever |55, rock this from beneath the abutment |54 and allow the switch to be closed rapidly by the spring |5I.

If the credit-registering mechanism is not in credit but is in arrears or debit, the collar |6| will have peen displaced by release of a collar |65 from the mechanism 2| and will no longer be in position to engage with the end |59 of the lever |51. This lever will therefore not be held in the position shown to retain the plate |46 and the latter will consequently rise again with the continued rotation of the pins |44, |45 and the subsequent operation of the latching lever |55 will be ineffective.

The credit registering mechanism is substantially of the kind already disclosed in British Patent No. 414,070 and its operation is briefly that the wheel |64 is moved relatively to the screwed shaft |63 in one direction by the coin mechanism and in the opposite direction by any of the various charges to be made, for example by the fixed charge collector and the meter mechanism |2. At a point where the credit of the user is exhausted a pin |64a carried by this trip wheel unlatches the collar |65 secured to the shaft |62 and allows the latter to move axially by the action of the spring |92 and thus be displaced from the path of the end |59 of the lever |51. This will allow the plate |46 to move upwardly under the influence of the spring |50 to open the switch. The incorporation of the second latching means constituted by the collar |6| and lever |51 relieves the collar` |65 from all strain due to switch latching and hence relieves any burden placed upon the motor driving the xed charge drive or the meter mechanism by such switch latching mechanism,

In order that the shaft |62 may be moved axially if necessary to present it to the catch mechanism of the registering mechanism 2| during the insertion of a fresh coin the chamfered face |60 of the lever |51 is adapted to engage the collar |6| during the movement of the lever |51 by the descending plate |46 and thus to move the shaft |62 axially to the right (Figure 10). If in the meantime suflicient credit has been imparted to the registering mechanism by the insertion of the coin, then this shaft will be held in an axial position more to the right than that previously assumed thereby by the catch mechanism of the device 2| and the lever |51 will afterwards abut thereagainst with its rear face, and its upper tongue |66 in engagement with the plate |46 will retain the latter in its lowered position.

Referring now to the meter gearing arrangements shown more particularly in Figure 13, it will be seen that the spindle 9| carrying the gear which is driven from the prepayment mechanism ||l has a crown wheel 92 (Figures 2, '1, and 13) and a gear Wheel 93 secured thereto. The crown wheel 92 is engaged by a pinion 94 secured to a staff 95 mounted in bearings upon the front plate 21 and carrying at its other end a further pinion 9.6 meshing with a crown -wheel 91 xed to the spindle .of vthe indicator'90 (Figures 1 and 13). The remaining indicators 99 and |00 are driven from the indicator 98 by pin and sprocket wheel mechanism The gear wheel 93 is in driving connection by .way of gear 254 with one sun wheel 255 of a differential gear device |02 (Figures 7 and 13), the other sun wheel 256 of which is driven from the fixed charge collecting device through gear train Ila (Figures 2 and 13). The planet carrier 251 of the differential gear |02 is secured to a staff |03. The movements of the two devices I0 and eective upon the differential gear |02 have a resultant which is given by movement of the staff |63. This stai is connected to a change gear device |86 (Figures 2, 4, and 13) `by means of which a price change compound |01 (Figures l, 2, and 13) can be inserted in -or removed from the transmission line at will. The gear change unit |86 comprises two gear wheels 2,50, 259 secured to a shaft 250. The gear wheels 25B, 259 are in constant driving engagement with gears 25|, 262 respectively both of which are carried by a gear shift lever 2|2, Figures 4, 17 ,and 18, pivoted about the axis of the shaft 200. The gears 26|, 262 are adapted to engage respectively with further gear wheels 263 and ,2|3 according to the direction in which the lever 2 I2 is moved. The gear 263 is secured to the staff |03 so that if this gear is engaged with the gear 26| the drive from the differential |02 to the shaft 260 is direct. If on the other hand the gear 2k6 is engaged by the gear 262 then the kdrive from the diierential |62 to the shaft 250 is by way of the price change compound |81 through a pinionZBd on staffY |03 and then through spindle. The drive from the shaft 260 is then to one sun wheel 21| (Figure 13) of a further .differential |88 the other sun wheel '212 of which is driven by the meter mechanism V2 through gear train 266. The planet carrier 261 of the differential y|08 is connected toa shaft 268 which is in geared connection by way of a pinion 269 with Aa long pinion H59 meshing with the trip wheel |64 of the registering mechanism 2| and operating yto screw this wheel vover a helical path backwards and forwards along the screwed shaft |63. The planet wheels 261 of the last-mentioned differential |93 are also connected by way of a suitable gear train 210 to an indicator |80 (Figures l. and 2) operating over the scale |03. The gear change `device |86 is adapted to be operated during the switch opening movement by means of a lever |9| (Figures 2, 4 and 9) the downwardly extending nose |9l of which, Figure 9, is engaged by .the plate |46 andmoved .upwardly therewith. The .lever i! also carries `a pin 2.!0 operating upon the cammed ,face 2|| of the gear shift lever.2|2. The gear lever 2|2 is shifted in one direction by movement. of the lever |9| upwards due to opening of the switch, the pin 2 i .IJ carried by the lever |9f| engaging the cammed face 2||, and in the other direction by engagement of a pin 2|5 on the plate ||5 witha.

cammed face 2|2' on the gear lever 2|2 when this is rotated at the next coin insertion operation. It will be understood that the cammed faces 2|! and 2|2 are on extensions Which may be integrally formed with the lever 2|2 carryingv the gears of the gear change device |86 which lever can be rocked slightly so that either gear wheel 2|3 or 2|3 is engaged depending upon the direction in which the lever 2|2 is moved. By this means thezindications given by the pointer |.90are in units unused While the mechanism is in credit and in the cash value of arrears when the mechanism is in arrears.

In order to warn the -user that the supply of electricity will shortly be cut on" owing to eX- haustion of credit, a warning device 23 is preferably provided. This devioe shown more clearly in fragmentary views (Figures 9, 10, 11, and 12) comprises an operating solenoid |68 secured to a part of the fixed frame and operable upon an armature |10 carried in a sleeve |1| of nonmagnetic material. This sleeve is connected to an extension |69 of the main switch rod |52 by a pin and slot connection which allows the latter to be operated in the normal manner previously described, by the meter mechanism without imparting movement to the armature |10.

The armature |10 is guided within pole tips |61 and |61a forming part of a magnetic circuit around the solenoid coil |68 and is normally located within the lower pole tip |61 so that when the coil |68 is intermittently energised, the said armature will be alternately raised and lowered to effect a similar movement of the switch rod |52 and thus cause flashing of any light connected to the users circuit. The upward movement imparted to the rod |52 by the solenoid is insuiiicient to cause latching -by the lever |55.

The intermittentl energisation of the solenoid |69 is effected by means of the mechanism illustrated more particularly in Figures 11, l2, and 16. This device comprises a crank lever |1I which is rigidly secured to the shaft 6| and therefore makes one complete revolution during each coin insertion. A lever |13 is loosely mounted on the same shaft 6| and is yalso slidable thereon in the direction of its length by the provision of a slot' |14. A spring |15 tensioned between a pin |16 on the lever and the shaft 6| tends to move the end of the lever |13 carrying a pin |12 outwardly in a radial direction. The pin |12 projects on both sides of the lever, one side being adapted for engagement in some circumstances with the crank lever |1| and the other side being arranged to project into a radial slot |18 in va-gear wheel |11 loosely mounted upon the shaft 6| and also, in some circumstances into a radial slot |19 formed in a stationary barrel |30. This barrel houses a helical spring |0| connected at one endto the barrel and at its other end to the gear wheel |11. The spring normally urges the gear wheel and therewith the lever |13 in an antiecloc'kwise direction (Figures 1l and 12). A further lever |82secured toa spindle 21| pivotally mounted in the fixed frame has a nose |-82a :which engages the pin |12 located within the slot |19 and serves, when required, to move the said pin and the lever |13 radially inwards .against the action -of the spring |15. The lever |82- is controlled by the trip device of the creditregisteringl mechanism 2| through suitable linkage in suchra manner that the said leveris moved to depress the -pin |12 inwardly when the credit mechanism reachesa position just prior to the instant ,of releaseof the collar 6| and the consequential opening of the main switch. This movement may be effected as shown in Figure Y noid |68 and the mainsupply.

The operation of this device is as follows. In normal circumstances, i. e., with the meter in credit, the spring I8| is tensioned and th'e mechanism is in the position shown in Figure 11. The approaching exhaustion of credit is marked by movement of the lever |82 to depress the pin |12 to a position where it is located wholly within the stationary barrel |88. As this pin is thus freed from the slotl |19 it is rotated together with the lever |13 and gear wheel |11 in an anticlockwise direction by the spring |8I until the pin engages with the crank lever I1I. This rotary movement of the gear |11 causes rotation of the gear |84 and the cam |84a to cause intermittent opening and closing of the contacts |85 and hence intermittent energisation of the solenoid |58. rThe number of times the solenoid is energised may be determined by the contour of the cam I84a or by the gear ratio between the gears |11 and |84.

During the next coin-insertion operation the crank lever |11 will be rotated through one revolution in a clockwise direction and this causes similar rotation of the pin |12, lever |13 and gear |11 and the winding up of the spring IBI until the pin |12 comes into alignment with the slot |19 in the barrel |80. The spring |15 then urges the pin |12 radially outwards to lock the mechanism in the position shown in Figure l1. It will be appreciated that the lever |82 has been raised by the restoration of credit in the mechanism 2|. The crank lever I1I is thus free to complete its revolution without the pin |12 and is also free to rotate idly during any subsequent coin-insertion operation while the mech.. anism is still in credit.

In order to permit operation of the switch contacts |85 only during the unwinding of the spring and not during reverse movement of the gear |11 upon stressing of the spring during the next coin insertion operation, a one-way drive such as a ratchet and pawl mechanism may be inserted between the cam I34a and its driving gear.

The operation of the complete mechanism is as follows: The flap 33 is lifted manually to uncover coin insertion aperture 3| and to cause movement of coin cage 25 and coin slot 29 into alignment with said aperture 3| A coin is next inserted and ap 39 released whereupon the latter is closed and the coin cage moved to the left (Figures 3, 5, and 6) by contraction of spring 36. Alignment of aperture 42 of cage 25 with coin testing chamber 44 allows the coin to fall into the latter where it is disposed between the light metal flap 50 and the metal insert 49 and rests upon the metal plate 52 on the top of the closure member 5|.

The circuit thus complete-d if the coin is conductive sets motor 24 into operation, which operation, once started, is continued for a cornplete cycle of the mechanism by the shunting contacts 59. The operation of the motor causes rotation of shaft 6| whereupon the nose |22 passes into notch I2| of cam |20 to allow plunger |25 to engage thickness dimension of coin in chamber 44.

If coin is too thin or is pierceable, lower end |20 of lever |23 carrying plunger |25 engages detent device |29 so as to rock shaft |30 which in turn causes depression of bar IIO by arm I3I. This lowering of bar releases forked lever 54 which results in rocking of spindle 53 and consequential movement of member to left (Figure 3) thereby allowing coin in chamber 44 to` fall into returned coinsI chute when plunger I 25 is subsequently withdrawn.

If inserted coin is of suitable thickness, detent device |29 is not moved and after plunger |25 has been withdrawn the release of cam follower 82 from proud portion of snail cam 8| allows spring |04 to move slide 88 to caliper the diameter of the coin in the chamber 44. Such calipering operation causes the multi-section gear unit 89 to be set at a corresponding position along the shaft so that continued rotation of latter shaft by motor 24 through gears 18, 19 brings notched disc |06 into co-operation with gauge plate |81. If the diameter of the inserted coin is not suitable, disc |05 will engage gauge plate |01 and cause rocking of bar |03 and trip lever |09 which in turn depresses bar ||0 to cause release of coin into returned coins chute as already described. Movement of trip lever |09 also unlatches plate I5 from gear 19 by movement of lever I I4 from pin I I3 so as to allow motor 24 to complete its cycle of operation without effecting further movement of shaft 80 which is thereafter immediately returned to its initial position by pressure of cam faced lever II8 upon cam |I9.

If the coin within chamber 44 is of suitable diameter then disc |06 passes through a notch in gauge plate |01 and does not rock bar |08. The consequent continued rotation of shaft 80 causes rotation of gear unit 89 and consequential movement of gear wheel 90 by an appropriate amount according to the particular section of the gear unit 89 which is effective thereon. This movement of the gear wheel 90 is transmitted to the gear |64 of the credit registering mechanism 2|.

The operation of the mechanism is continued and eventually pin |43 on gear 18 engages lever 54 so as to rock it in an anti-clockwise direction (Figure 4). If the coin has already been released on account of unsuitable thickness or diameter, the fork of the lever 54 will be entered and the lever returned to its normal position and latched behind the lug of the bar I I0. If however the coin has proved suitable the said lever will still be latched and will be engaged by the pin |43 on the outside of the fork with the result that the said lever will be moved in an anti-clockwise direction (Figure 4) to an extent suiicient to cause rocking of the interconnected member 5| to the right (Figure 3) so as to allow the coin in the chamber 44 to fall into a coin till.

During each cycle of operation of the mechanism with either a suitable or an unsuitable coin, the gears 18, 19 and pins |44, |45 thereon are rotated one revolution. If the switch |53 controlling the current supply is already closed the pins rotate idly but if it is open the said pins engage and depress plate |45 to stress spring |5I anchored at its other end to switch rod |52 which is held latched in its upper position by lever |55. Depression of plate |46 rocks catch lever I 51 which, if credit has been restored, locks up upon collar |6| and thereafter holds plate |46 in depressed position with spring |5| stressed. At a point near the end of the operative cycle of motor 24, latching lever |55 is tripped by pin |55 to allow switch rod |52 to descend rapidly under the action of spring |5I to close switch |53. 'I'he subsequent opening of the switch is effected when credit is exhausted by the removal of collar IBI from beneath end'of catch lever |51 whereby tension of spring |5| is removed and the `previously compressed spring |50 alagencies lowed to become efective to raise the switch rod |52.

Warning of the approach of exhaustion of credit is given by the engagement of pin ltloi` on gear wheel |54 with lever 2|t just prior to the opening of switch |53. Movement of lever 2|6 causes rocking of lever |82 to project pin |12 insi-de barrel |80'. Removal of pin from slot |19 allows stressed spring |8| t0 rotate lever |13 and gear |11 thereby driving cam |8401r tov cause opening and closing of contacts |85 which in turn cause intermittent operation of solenoid' |68. Energization of solenoid |68 attracts armature to lift switch rod |52 to open switch |53.

The opening and closing movements of the switch rod 52 are transmitted by means 0f lever |9| to the gear change device |86 so that when switch rod |52 is lowered the device |86 is operated to insert the price change compound |81 between the watthour meter mechanism I2 and xed charge Collector and the indicator |93 whereby the indications of the latter can be made in unused units of electricity, irrespective of the particular price per unit charge (determined by the ratio of the price change compound) whereas when switch rod |2 is raised (on account of credit exhaustion) the device |86 is operated to couple the fixed charge collector and prepayment mechanism i3 directly to the pointer |90 without the price change compound so that all Y arrears indications are in actual cash values.

One alternative embodiment is illustrated diagrammatically in Figure ifi where a push button is employed and is irst movable to a variable extent to caliper a coin. rThis variable movement is arranged to control a contact making operation depending upon its adjusted position engaging the coin. As shown a push button 22d is slidabiy mounted in bearings, not shown, in a casing and is connected at its inner end toa plunger 22 operating into a sleeve 222 against a strong Spring 223 disposed between the closed end of the sleeve and the end of the plunger. The outer face of the closed end of the sleeve 222 is used as the movable member for calipering a coin .r against a stationary abutment 22d. Any movement of the sleeve by the push button 22E! is opposed by a weak spring 225 anchored at its other end to a Xed part of the device. The sleeve is connected to one end of an oscillating contact arm 226 pivoted at a point 221 such that the contact engaging end 22S executes an ampliiied movement to the end connected to the sleeve. This latter end sweeps over a number of contacts 229 and in dependence upon the calipered diameter of the `coin rests upon one or other to set up a circuit through one of a number of electromagnets 23?. These magnets -actuate by ratchet and pawl mechanism a shaft 23| to Varying eX- tents according to the respective values of the coins engaged between the sleeve 222 and the abutment 224. The shaft 23| is in geared connection with the credit registering mechanism of the device. A further pair of contacts 232 are arranged in series with the switch arm 226 and contacts 229 so that after gauging the coin by the push button 220 to move the sleeve 222 against the weak spring 225 and so to choose a magnet 239 in accordance with the value of the coin, it is then necessary to press harder to overcome the pressure .of the strong spring 223 and so cause closure of the contacts 232 to energize the :particular magnet selected. The operation of this magnet effects the registration of credit in accordance with the value of the coin being calipered. The contacts 232 may also serve to close the energizing circuit of av winding 232 for operating the switch closure device. l

The above described constructional embodiment is a preferred form of the invention, but it will be understood that there are many alternative mannersl of carrying out the invention as denned in the attached claims.

I claim:

l. A multi-coin electricity supply meter comprising, a casing having a coin insertion aperture, a coin testing chamber receiving coins inserted in said casing through said aperture, calipering means for ascertaining the -diameter of a coin in said testing chamber, credit registering means, operating means for said credit registering mechanism variably controlled by said calipering means in accordance with the diameter of the inserted coin, an electric supply switch, switch closing means for said electric supply switch, an electromagnetic device, gearing linking said electromagnetic device successively to each of sai-d calipering, credit registering and switch closing means, and contacts for completing an energising circuit for said electromagnetic device upon insertion of a proper coin in saidI casing through said coin insertion aperture.

' 2. A prepayment electricity meter comp-rising, coin handling mechanism including coin receiving and coin testing means in which an inserted coin is arranged to travel step by step through the mechanism, an integrating meter for recording the consumption of energy, credit registering mechanism and means for operating the same in a credit direction in accordance with the operation of said 4'coin handling mechanism and in a debit direction by said meter, and means controlled by said credit registering lmechanism when the latter is in a position approaching zero credit for automatically and momentarily interrupting the supply circuit through said meter and for interrupting the supply when zero credit is reached until a fresh coin is inserted.

3. A prepayment electricity meter comprising, in combination, a casing having a coin insertion aperture, a coin testing chamber, calipering means operable to gauge the diameter of a coin in said testing chamber, Ythickness testing means arranged to gauge the thickness of a coin inserted in said coin testing chamber, Aan electric driving motor, means operatively connecting said calipering means and said thickness testing means with said driving motor, a shaft, credit registering mechanism, a variable ratio gear drive between said shaft and said credit registering mechanism, means for adjusting said Variable ratio drive in dependence upon the operation of said calipering mechanism, a device for providing a source of power supply to said driving motor upon insertion of a coin so as to cause complete operation of said calipering and said coin testing mechanisms, and a coupling member between said motor and said shaft controlled by predetermined operation of said calipering and thickness testing devices for transmitting movement from said motor to said shaft in the event of correct coin insertion and for preventing complete movement of said shaft in the event of incorrect coin insertion whereby said registering mechanism is operated only by the insertion of a correct coin.

4. A prepayment electricity meter comprising, coin handling mechanism in which an inserted coin is arranged to travel through the mechanism, an integrating meter responsive to the energy consumption through said meter, credit registering mechanism operable in a credit direction by said coin handling mechanism and in debit direction by said meter, a iiXed charge mechanism, an indicating dial driven conjointly from said credit registering mechanism and said xed charge mechanism, a gear change unit, and means operated by said credit registering mechanism at the point of zero credit for operatively connecting said gear change unit between said iixed charge mechanism and said indicating dial for causing the arrears to be indicated in monetary values.

5. A prepayment mechanism comprising, in combination, means for metering a commodity, means for receiving coins having different sizes each corresponding to a diierent value, means registering credit in accordance with the total value of the coins received and in response to the receipt of the same, means causing the commodity to be available on registration of credit by said credit registering means, iixed charge means -continuously operable regardless of Whether or not credit is registered 'and cooperating with said credit registering means to diminish the credit registered thereby, means for making said commodity available until the credit registered by said credit registering means is exhausted as a result of conjoint operation of said commodity metering means and said fixed charge means or operation of the latter alone, indicating means; means operatively connecting said commodity metering means, said credit registering means and said iixed charge means to said indicating means while credit is registered to indicate the commodity units yet available; and additional means operatively connecting said credit registering means and said fixed charge means to said indicating means after credit is exhausted to indicate the debit in coin units.

6. A prepayment mechanism comprising, in combination, means for metering a commodity, means for receiving metallic coins having different sizes each corresponding to a different value, an electric motor, circuit means for connecting said motor to a current source including circuit connections completed on receipt of a metallic coin, means operated by said motor for testing the thickness of said coin, means controlled by said thickness testing means for rejecting a coin the thickness of Which is below a predetermined value, means operated by said motor subsequent to testing the thickness of said coin for testing the diameter thereof if it has not been rejected, means operated by said motor in accordance With the diameter of said coin, and means controlled by said commodity metering means for dispensing said commodity in an amount corresponding to the diameter of said coin.

7. A prepayment mechanism comprising, in combination, means for metering a commodity, means for receiving metallic coins having different sizes each corresponding to a different value, an electric motor, circuit means for connecting said motor to a current source including circuit connections completed on receipt of each metallic coin, means operated by said motor for testing the thickness of each coin, means controlled by said thickness testing means for rejecting each coin the thickness of which is less than a predetermined value, means operated by said motor subsequent to testing the thickness of each coin for testing its diameter if it has not been rejected, credit registering means, means operatively interconnecting said credit registering means and said motor whereby the former is operated by the latter to an extent depending upon the total value of the coins received, means causing the commodity to be available on registration of credit by said credit registering means, and means cooperating With said commodity metering means for rendering said commodity available in an amount depending upon the credit registered by said credit registering means.

GEORGE EDWARD WESTON. 

